John Deere Js20 won't start after i stop to take a 15 minute break.

I got a lawnmower from my friend, he said it wouldn't run. But honestly all I did was put gas in it. He said it sat behind his house for 5 years. So I fill the tank up and pulled it 2 times and it fired right up. So he said I could have it. I got it home and changed the oil, spark plug, and air filters. And I know I shouldn't be mowing this much grass with a push mower, but I do because I need the exercise haha. So the property is 5 acres andi used it all last year (2011) with it starting on the first pull everytime. I could go outside in the middle of winter and pull it once and it would start. But this year it started acting up :( . It starts on the first pull when the motor is cold, but once you get the engine warmed up, and stop for 25 minutes, I will pull and pull 15-20 times for it to start. After it sits there and cools for a few hours, it will start right up. Any ideas what this could be???

Re: John Deere Js20 won't start after i stop to take a 15 minute break.

Originally Posted by possum

Look into the choke mechanics if a Briggs. The thermostat behind the muffler could be bad or the swinging parts sticking on shaft, springs broken or unhooked, debris built up on springs and parts etc.

I just removed the muffler earlier today, and that thing seemed to move freely and before I tore it down I put 3 in 1 oil on everything and was ok. Btw would loss of compression cause this to happen bcause I removed the head and found a torn head gasket?!??!!?

Re: John Deere Js20 won't start after i stop to take a 15 minute break.

Does it shut off after warming up ? . If you didnt stop would it stay running for a hr straight ? . I had a customer with a js20 and his would run for 20-30 minutes and shut off and need to cool down and it ended up being the valves.

Re: John Deere Js20 won't start after i stop to take a 15 minute break.

Originally Posted by jetrail

Does it shut off after warming up ? . If you didnt stop would it stay running for a hr straight ? . I had a customer with a js20 and his would run for 20-30 minutes and shut off and need to cool down and it ended up being the valves.

Yeah it will Stay running all day long if I keep it running. It will start back up right after I cut it off and fill the tank with gas, but once you let it sit for 10-20 minutes and try to pull it, it just wont start up.

Re: John Deere Js20 won't start after i stop to take a 15 minute break.

fix the head gasket and it sounds to me like it could be flooding, it sits a little long and fills with fuel, seeping through needle slightly maybe. put a shut off valve on it, when you stop to take a break turn the fuel off, see what happens when you come back to start it.

Re: John Deere Js20 won't start after i stop to take a 15 minute break.

Originally Posted by twinfords

fix the head gasket and it sounds to me like it could be flooding, it sits a little long and fills with fuel, seeping through needle slightly maybe. put a shut off valve on it, when you stop to take a break turn the fuel off, see what happens when you come back to start it.

Alright I will try that, and when you said something about the valves causing that to happen, if that's the problem, how would I fix it?

Re: John Deere Js20 won't start after i stop to take a 15 minute break.

i did not say fix the valves, i said install a fuel shut off valve, if it is OHV they could need adjustment. you will need to find specs on what they are supposed to be set at. check them out when you have the head off to fix the gasket etc.

Re: John Deere Js20 won't start after i stop to take a 15 minute break.

Originally Posted by twinfords

i did not say fix the valves, i said install a fuel shut off valve, if it is OHV they could need adjustment. you will need to find specs on what they are supposed to be set at. check them out when you have the head off to fix the gasket etc.

Ok I replaced the head gasket, put on a shut off valve, rebuild the carb, and oil the autochoke and I mowed for about an hour, stopped for a 15 minute break, same d*mn thing, I pulled five or six time and it started. When I pull it, I sounded like it was popping in the carb. And it does actually feel like it it turns over real easy when I pull it too.

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